Telephone-exchange system.



1 L. WRIGHT. TELEPHONE EXCHANGE SYSTEM. i APPLICATION FxLED lugNE 9.1914.

1,191,265, V Patented July 18, 1916. 2 SHEETS-SHEET 1.

J. L. WRIGHT.

TELEPHONE EXCHANGE SYSTEM.

APPucATloN man :um: 9. 1914.

1 1 9 1,265. A Patented July 18, 1916.

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JOSEPH L. WRIGHT, OE CLEVELAND, OHIO, ASSIGNOR, RY ivrEsNE ASSIGNMENTS,To WESTERN ELECTRIC COMPANY, INCORPORATED, A CORPORATION OE NEW YORK.

TELEPHONE-EXCHANGE SYSTEM.l

Specification of Letters Patent.v Patented, July 18, 1916.

Application led lune 9, 1914. Serial No. 844,006.

To all whom it may concern:

Be it known that I, JOSEPH L. WRIGHT, a citizen of the United' States,residing at Cleveland, in the county of Cuyahoga and State of Ohio, haveinvented certain new and useful Improvements in Telephone-EX- change"Systems, of which the following is a specification.

My invention relates to telephone exchange systemsand lespecially toythat type wherein automatic switching mechanism is used for eifectingconnections between calling and called subscribers or between varioustrunks.

I-Ieretofore it has been customary to transmit impulses from a sendingdevice in a predetermined order to operatel the automatic switches.These sending devices may eitherv be at the central oHice or at asubscrlbers station and transmit impulses by grounding one or both sidesof the line, or as in metallic systems by opening and closing the lineor trunk circuit. With the latter method special apparatus havingvarious time elements has to be provided at the central oiiice. Thisapparatus usually consists' of quick and sluggish acting 4relays whichhave to be' y timed very carefully in order that theautomatic switchingmechanism which they control is properly operated.

Vith my invention I preferably use a metallic circuit but do not openand close the line circuit as the control circuit is normally closedwhile the switches are being operated. To accomplish this end Iprovi'dea sound or audible signal producing device at the substation orat the central otice as the case may be. Associated with the automaticswitching mechanism is apparatus which responds tothe sound producingdevice. The appa-y ratus which responds to the sound producing devicecorresponds to the ordinary receiver and is provided with a set ofcontacts which open and close in response to the action of the soundproducing device. With this method of controlling the automaticswitching mechanism the subscriber upon removing his receiver operatesthe device and the circuit of thisline is noty opened until he nallyhangs up his receiver, thereby providing a positive method of releasefor the automatic switches. Y

My Vinvention is illustrated in the accom-Y panying drawings wherein: i

Figure l shows a subscribers station termlnating in a irst selectorswitch. Fig. 2 shows a connector circuit which operates in conjunctionwith the first selector circuit. Fig. 3 shows a sound producing devicesuitable -or` use with my invention. Fig. 4 shows a modification of theapparatus which responds to the sound producing device.

, Referring to Fig. 1, the subscribers station at rA is equipped withapparatus usual in common battery systems comprising the usual receiver,transmitter, switch hook and ringer, and in addition is equipped withthe sound producing device shown in detail in Fig. 3, and represented inFig. 1 by the letter P. I Y

The subscribers line terminates at the central oflice in the firstselector Switch K. This switch corresponds to that of the wellknown`Strowger type but instead oi' first stepping vertically and thenrotating, it iirst rotates and then steps in a vertical direction. Relay1-B, is the tip relay responsive to the closing of the callingsubscribers line. The receiving device is shown at D in a diagrammaticmanner. The magnet 15 is surrounded by disk type permanent magnets usedin watch case receivers. The diaphragm 17 is provided with a Contactpoint 19 which engages contact 18 when in its operative position. Thereceiving device is in reality a polarized relay constructed on theprinciple of a telephone receiver. The diaphragm corresponds to andperforms the same function as the armaturef'of a` relay. TheI diaphragmin vibrating operates its associated contacts which in turn controlother mechanism. The magnet 15 `consists. of a core with a suitablewinding in the ordinary manner. The disks 16 which surround theVvmagnet` are ring shaped permanent magnets which serve to magnetize orpolarize the magnet 15. The diaphragm 17 may be clamped and held inplace in a manner similar t0 a diaphragm in ordinary telephonereceivers.

Any form of adjustment may be used to regulate the space between thecontact points 1S and 19 in order to cause these contacts to properlyoperate in response to the signals transmitted. 1

Relay F is a repeating relay, while relay G is a slow relay forcontrolling the various circuits. Relay E is the test relay while relay200 is the cut-oli' relay serving to dis-` connect the first selector onincoming calls.

Referring to Fig.

is shown at L and switch equipment test relay.

Fig. l shows the manner in which the motion of the diaphragm in thereceiving device is multiplied. An arm is provided and pivoted at 100.rlhe shorter portion of the arm terminates in a button 102 whichnormally rests in engagement with the diaphragm 17. phragm the armfollows and the portion at 101 which is considerably longer than that at103, moves a greater distance and at each movement closes the contactsprings 18 and 19.

The operation of my system is as follows: rlhe subscriber at A removinghis receiver closes his line circuit thereby energizing relay l-B. Theenergizing of this relay connects ground to contacts d8 which aremultipled in the banks of the connector switches so as to render theline busy against other calls. rllhe operation of relay l-B alsodisconnects or breaks the circuit of thc release magnet J. Battery issupplied to the calling subscriber for talking purposes through thewindings of relay l-B and the retardation coil C.V The talkingconductors are separated by condensers 7 and 8 in the usual manner. Thecalling subscriber after removing his receiver operates the soundproducing device F a number of times correspending to the number desiredin the usual manner.

The winding of .the magnet 15 of the receiving device is connected tothe talking conductors 9 and 10, one terminal being permanentlyconnected to the conductor 10 while the other terminal is connected tothe conductor 9 through the cam springs 35 and 86. At each operation o-fthe sound producing device at the subscribers station a correspondingaction is set up in the receiving device at D. The receiving device D inacting completes the circuit of relay F and slow relay G as follows:ground, 18,

At each operation of the dia-` 19, 20, winding' of relay F, 21, windingof relay G, to battery B. The operation of relay F completes the circuitof the rotary magnet as follows: ground, contacts of relay F, 22,contacts of relay E, 25, winding of magnet H to battery B. The operationof magnet ll causes the switch l to rotate and bring the wipers 13 andle in line with a row of contacts Correspending` to the action of thesound producing device. cach stroke of the magnet H its associatedcontact springs are closed thereby connecting ground between thewindings of relays F and G. rlhis ground connection shunts out relay Fbut maintains relay G energized. Relay G is first energized in serieswith relay F by the action of the receiving device and then heldenergized by the action of the springs associated with the rotary magnetll. The magnet G, being slow, remains energized throughout theinterruptions caused by the opening of contacts 18 and 19 of thereceiving device D. 'lhe relay F is provided with a locking Contact andwhen energized by the closing of contacts 18 and 19 its circuit ismaintained to ground independent of the contacts 18 and 19. This lockingcontact is provided in view of the fact that contacts 18 and 19 may beonly momentarily closed, that is to say, not closed long enough to allowthe full operation of the magnet H. rllhis momentary closure, however,is sufhcient to energize relay F and as soon as the magnet H hasi'inished its stroke ground is connected and relay F shunted out orreleased.

After the iirst operation of the sound producing device at thesubscribers station ,il there is a momentary pause due to the subscribersetting up the number for another series. During this pause relay Gfalls back. Relay G in falling back completes the circuit of relay E asfollows: ground, cam springs 4.0, 39, and 38, conductor 37, backcontacts of relay F', 32, contacts of relay'G, 31, vertical cam springs80 and 29, 2S, winding of relay E to battery rllhe rotary cam springs38, 39 and 4.0 are closed at the irst rotary step of the switch K. Thevertical cam springs 30, 29, 30 and 35 are opened at the lirst verticalstep of the switch K.

The operation ofrelay E severs the trunk conductors, disconnects therotary magnet H and in its place connects the vertical magnet l. Theoperation of relay E also con pletes the circuit of relay F as follows:ground, contacts of relay E, 33, 20, winding of relay F, 21, winding ofrelay G to battery B. The operation of relay F now completes the circuitof the vertical magnet l as follows: ground, contacts of relay F, 22,contacts of relay E, 23, winding of magnet l to battery B. The operationof magnet 1 causes the switch K to step vertically and y.to

also by means 0f its associated contact springs, connects ground betweenthe windings of relays F and G. This ground connection shunts relay Fthereby opening the circuit of magnet I, but as soon as magnet `contactis found, relay E will restore and remove ground from the winding ofrelay F. Relay F, in falling back, applies ground to test brush 14, thuscausing the seized trunk to test busy. The next operation of the soundproducing device at the subscribers station causes the operation of thereceiving device L in Fig. 2. The action of the receiving device Lcompletes the circuit of relay M and slow relay N as follows: ground,G1, 60, 64, winding of relay M, 65, winding of relay N to battery B. Theoperation of relay M completes the circuit of the rotary magnet 1V asfollows: ground, contacts of relay M, 66, contacts of relay V, 67,winding of magnet lV to battery B. The operation of magnet W closes itsassociated contact springs thereby connecting ground between thewindings of relays M and N. This ground shunts out the windings of relayM but maintains the relay N energized. After the final operation of thereceiving device L, relay N falls back and completes the circuit of therelay V as follows: battery B, contacts of relay N, G8, cam springs G9,and 70, conductor 71, cam springs 7 2 and 73, winding of relay V, 57,test contacts, wiper 14, 27, to ground through the back contacts ofrelay F (Fig. l). Relay V then locks up. The operation of relay Vdisconnects the winding of the rotary magnet lV and in its placeconnects the vertical magnet X. The next operation'of the receivingdevice L in response te the action of thesound producing device at thesubscribers station completes the circuit of relays M and N as before..The operation of relay M now completes the circuit of the verticalmagnet X as follows: ground, contacts of relay M, G6, contacts of relayV, 75, windingV of magnet ,X to battery B. The operation of magnet Xbesides stepping the `switch Z in a vertical direction also closes itsassociated contact springs thereby connecting ground between thewindings of relays M and N. After the third operation of the soundproducing device at the subscribers station relay N falling backcompletes the circuit of relay S as follows: ground, 76,

winding of relay S, 77, wiper 78, contact 47, 44, winding of relay 200to' battery B. The operation of relay S completes the circuit of theringing relay T as follows: ground, commutator 90, winding of relay T,89, contacts 'of relay S, 88, contacts of relay R to' battery B. Theoperation of relay S also completes the circuit of relay U in case thecalled for line is not busy as follows: ground, contacts of relay 300,86, contacts of relay S, S7, winding of relay U to battery B. Theoperation of relay U completes the trunk conductors and also connectsground to the test wiper SO of the switch Z thereby rendering the calledfor line busy against other calls. f

In case the called for line is busy groun would be connected to the testcontacts engaged by the wiper 80 and in such an event after relay N hadfallen back the circuit of of release magnet Y thereby restoringV theconnector switch Z to its normal position. The operation of relay 300connects a suitable busy tone signal lto the trunk conductors notifyingthe calling subscriber that the called for line is busy.

The action of relay 300 besides performing the foregoing functions, alsoprevent-s the operation of relay U by removing ground from the conductor86. It will be noticed that when relay N finally restores after thewipers of the switch Z engageV the contacts of the called line that theaction of relay S and relay 300 would be completed at the same time, butthat the action of relay U is no-t completed until after the action ofrelayS. This arrangement causes sufficient time interval for'theoperation of relay 300 in case the called for line is busy and beforerelay U can operate. Upon the lirst operation of relay N the circuit ofrelay R is completed asfollows: battery B, contacts of relay N, 58,winding of relay R to ground over test wire 57. The operation of relay Rpartially completes the circuit of relay T and partially opens thecircuit of release magnet Y. Oney terminal of magnet Y is connected toground through the rotary cam springs 94 controlled byscriber removeshis receiver relay O is energized, the operation of which closes the tiptrunk conductor and also removes battery from the locking contact ofrelay R. Relay R restoring opens the circuit of relay T thus preventingfurther application of ringing current. Battery is supplied to thecalled subscriber through the winding of relay O and winding of theretardation coil Q3. At the termination of the conversatio-n the callingsubscriber hanging up his receiver opens the circuit of hisline'thereby'causing the denergization of relay l-B, This relay inrestoring completes the circuit of the release magnet J as follows:ground, 40, 39, tl, contacts of relay l-B, a2, winding of magnet J tobattery-B. rlhe action of this release magnet restores the firstselector switch K thereby restoring all its parts to normal. g

rlhe called subscriber hanging up his receiver causes the denergizationof relay 0 and this relay in restoring completes the circuit of therelease magnet Y as follows: battery B, contacts of relay O, 85,contacts of rela-y R, Se, winding of magnet Y, rotary cam springs 9a toground. rlhe operation of magnet Y restores the switch Z to its normalposition thereby causing relays S and U to return to their normalcondition.

ln case the called for subscriber does not answer then the callingsubscriber in addition to releasing the first selector switch K alsoreleases the connector switch Z. When the calling subscriber hangs uphis receiver restoring the first selector switch K ground is removedfrom test wire 57 of the connector switch thereby releasing relay R.This relay in restoring completes the circuit of the release magnet Yjust as though the called for subscriber had answered and then hung uphis receiver.

Having thus described my invention, what l desire to secure by LettersPatent is:

l. ln a telephone exchange system, the combination with an automaticswitch, a stepping magnet therefor, and a sound producing device, of aplurality of trunk circuits selectable by said switch, a receivingdevice associated with said switch and responsive to said soundproducing device adapted to transmit impulses to said stepping magnet tocause said automatic switch to select any one of said trunk circuits,substantially as set forth.

2. In a. telephone exchange system, the combination with an automaticswitch, a stepping magnet therefor, and a receiving device, of a soundproducing device adapted to actuate the same, a plurality of circuitsselectable by said switch, said receiving device being adapted totransmit impulses to said magnet to cause said automatic switch toselect any one of said circuits, substantially as set forth.

3. In a telephone exchange system, the combination with a plurality ofsubscribers lines, of automatic switching mechanism for selecting saidlines, sound producing means, a stepping magnet for operating saidswitching` mechanism, additional means associated with said automaticswitching mechanism responsive to said sound producing means foroperating said stepping magnet to cause said automatic switchingmechanism to select said lines, substantially as set forth.

Ll. ln a telephone exchange system, the combination with a calling and acalled subscribers line, of automatic switching mechanism for selectingthe called line, a stepping magnet therefor, means. associated with saidautomatic switching mechanism and responsive to audible signals over thecalling line for transmitting impulses to said magnet to cause saidautomatic switching mechanism to select the called line. substantiallyas set forth. v

5. ln a telephone exchange system, thc combination with an automaticswitch, a stepping magnet therefor, of a plurality of circuitsselectable by said switch, an audible controlling device, meansassociated with said switch and responsive to said audible device fortransmitting impulses to said magnet to cause said automatic switch toselect any one of said circuits, substantially as set forth. v Y

6. ln a telephone exchange system, the combination with an automaticswitch movable in two directions, of a sound producing device, meansassociated with said switch and responsive to said sound producingdevice for controlling` the action of said switch in both directions,substantially as set forth.

7. ln a telephone exchange system, the combination with an automaticswitch movable in two directions, means for actuating said switch inboth directions, sound producing means, said actuating means beingresponsive to said sound producing means, substantially as set forth.

S. in a telephone exchange system, the combination with a two-motionstep-by-step automatic switch, means for actuating said switch, a devicefor producing audible signals, additional means associated with saidswitch for controlling said actuating means in response to said audiblesignals, substantially as setforth.

9. ln a telephone exchange system, the combination with a two-motionstep-by-step automatic switch, a device for producing audible signals,said actuating means being tuned to and responsive to said audiblesignals, substantially as set forth.

10. ln a telephone exchange system, the combination with a two-motionautomatic Switch, of a device for producing a predetermined number ofaudible signals, actuating means for said switch, additional meansassociated with said switch responsive to said audible signals foractuating said switch, laccording to the number of audible signals,substantially as set forth.

11. In a telephone exchange system, the combination with a two-inotionautomatic switch, of a device for producing distinctive audible signalsin a predetermined order, means associated with said switch timed to andresponsive to said signals for controlling said automatic switchaccording to the order of said signals, substantially as set forth.

12. In a telephone exchange system, the combination with a device forproducing a predetermined number of audible signals, of an automaticswitch provided with a plurality of contacts selectable by said switch,means for actuating said switch, additional means associated with saidswitch responsive to said audible signals for rendering active theactuating means'to cause said switch to select a contact correspondingto the number of audible signals, substantially as set forth.

18. In a telephone exchange system, the combination with a plurality ofsubscribers lines, of an automatic switch for selecting said lines, acontrol circuit extending to said switch, means associated with saidcontrol circuit for causing current variations therein, a receivingdevice, means for inductively associating said receiving device withsaid means whereby the same is responsive to said variations in thecontrol circuit for causing said switch to select any one of said lines,said variations occurring while said control circuit is closed,substantially as set forth.

14. In a telephone exchange system, the combination with an automaticswitch, actuating and releasing means for said switch, a control circuitcomprising two conductors extending to said switch, means for closingsaid conductors, a device for causing current variations in said controlcircuit durscribers station associated with said control circuit, saidstation comprising a circuit closing device for closing said conductorsand a sound producing device, means asso- `ciated with switch responsiveto the circuit closing device for controlling the releasing means, andadditional means comprising a receiving ldevice responsive to the soundproducing device for controlling the actuating means during the'closureof said conductors,

substantially as set forth.

16. In a telephone exchange system, 'the combination with an automaticswitch, actuating and releasingmeans for said switch', ak

control circuit comprising two conductors extending to said switch,means in said .control Vcircuit for closing said conductors, additionalfor causing variations therein, means associated with said switches forcontrolling their action to interconnect said lines, said meanscomprising receiving devices responsive to said variations,substantially as set forth.

18. In a telephone exchange system, the combination l with calling andcalled subscribers lines, of automatic switching mechanisin forinterconnecting said lines, audible signal devices associated with saidlines, receiving devices associated with said automatic switchingmechanism responsive to said signal devices for automatically causingany one of the calling lines to become connected to any one of lthecalled lines, substantially as set forth.

19. In a telephone exchange system, the combination with an automaticswitch and a control .trunk leading thereto, actuating means for saidswitch, sound producing means associated with said control trunk forcausing variations therein, a receiving device associated with saidswitch responsive to said variations for controlling the actuating meansfor said switch, substantially as set forth.

20. In a telephone exchange system, the combination with a calling and acalled subscribers line, sound producing means therein, of automaticswitching mechanism for iiiterconnecting said lines, said automaticswitching mechanism comprising selector and connector switches, meansassociated with said switches controlled by said sound producing meansfor causing said switches to interconnect said lines, substantially asset forth.

21. In a telephone exchange system, the combination with a calling and acalled subscribers line, of automatic switching mechanism comprisingselector and connector switches for interconnecting said lines, anaudible signal device associated with the calling line, of meansassociated with said switches responsive to said device for causing theselection of the called line by said switching mechanism, substantiallyas set forth.

22. In a telephone exchange system, the combination with calling andcalled subscribers lines, of automatic switching mechanism comprisingselector and connector switches for interconnecting said lines, anaudible signal device, means associated with said switching mechanismresponsive to said device for causing the interconnection of said lines,substantially as set forth.

23. In a telephone exchange system, the combination with an automaticswitch, actuating means for said switch, of a sound producing device, areceiving device associated with said switch and controlled by saiddevice for rendering operable said actuating Ameans, a locking relayassociated with said switch, means controlled by said receiving devicefor energizing said relay, and additional means controlled by theactuating means for denergizing said relay, substantially as set forth.

24. In a telephone exchange system, the combination with a calling and acalled subscribers line, of automatic switching mechanism forming thelink for interconnecting said lines, a stepping magnet for saidswitching mechanism, sound producing means associated with the callingline, means associated v.

with said automatic switching mechanism responsive to said soundproducing means for transmitting impulses to said magnet to cause saidautomatic switching mechanism to form the link for interconnecting saidlines, substantially as set forth.

In testimony whereof I afix my signature in presence of two witnesses.

JOSEPH L. VVRIGIIT.

Witnesses:

A. FRANKCOUNTS, GEO. F. PONTINE.

Copies of this patent may be obtained for ve cents each, by addressingthe Commissioner of Patents, Washington, D. C.

